From: Mark Mallinson
Subject: Product launch
Date: 19 April 2011 06:08 "I am writing to you as president of Resonessence Labs. Until quite
recently I was the operations director of ESS Technology Inc. and headed
up the team responsible for designing the Sabre Audio DAC chip.
As you know that chip is now regarded as the world's best
audio DAC and has been designed into the most high-end digital audio systems.
I am proud to announce that Resonessence Labs is ready to launch its
first product, Invicta. I encourage you to
read through our user guide and in particular the technical measurements.
In the guide we go into great detail on how our system performs in the
lab. I think that you will find the Audio Precision data impressive.
What's more important of course is how our system measures up in
listening tests. I can assure you that it is outstanding." -
Mark Mallinson

I was reminded of Orpheus Labs. At the time they began their operations as a proof-of-concept subsidiary to fully demonstrate Anagram's digital silicon prowess beyond uncontrollable and possibly inferior OEM applications. In the valve audio sector Trafomatic Audio was launched to showcase Sasa Cokic's Trafomatic transformer craft. With their Invicta converter Resonessence—what a suggestive name—promises to be a best-case demonstrator for the ESS chip as envisioned by its own creators. I would simply hesitate over point blank declarations over world's best. AKM, BB/TI and Wolfson remain strong contenders, their chips the top choice for Esoteric, April Music Eximus, Chord and Antelope Audio among others. More vitally there's more to cutting-edge digital product than chips. How current/voltage conversion and analog stages as well as power supplies are executed is probably more important. That explains how analog companies like Burson and Yamamoto managed to author competitive digital models. Or as well-known audio designer Demian Martin put it: "The measured performance of the ESS chip is exceptional but getting good sound out of it is quite difficult, like any DAC. The ESS promises easier implementation since so much is on the chip. But that could be a trap if the details are not just right. Their demo board can measure very well but doesn't seem to sound as good as the measurements suggest. Some of us believe the DAC chip isn't really the choke point in good digital reproduction today. Execution of the stuff around it has more influence on the sound than the particular converter or its topology."

In development for two years, the Canadian Invicta team certainly did not rush their first 'Sabre by Sabre' model. The frontal SD card slot alone is unusual in this product category and the very informative low consumption organic light-emitting display with multi-function control not the norm either.

Three BNC rather than RCA coaxial inputs on the rear suggest further seriousness of purpose. So does the segregation for electromagnetic decoupling beneath the bonnet of the aluminum extrusion; low-inductance surface-mount parts; and a linear rather than switching power supply decoupled with series inductors and smoothed with "vastly overspecified capacitors" to feed high-performance linear regulators supported with discrete and additionally filtered devices to handle the primary current flow.

An off-the-shelf high performance regulator chip is only used for its internal
reference and as current limit and closed loop controller.
The asynchronous USB input* isn't solely for streaming audio. It's also to download firmware updates of three kinds: the USB firmware; the code that runs the configurable hardware engine; and the configuration code that programs the FPGA and its series of MicroBlaze2 Xilinx Spartan 6 soft processor cores. The on-chip re-synchronization of the ESS core is optimized with "a precision ultra-low phase
noise oscillator. The precise phase and frequency relationships
of these clocks is crafted to best exploit the
asynchronous sample rate converter of the Sabre DAC. The resulting audio signal actually exceeds the performance of the industry-standard measurement machines."
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* The review unit's Cypress Semiconductor USB transceiver was programmed for USB Audio Class 1.0 and limited to 24/96. A subsequent USB Audio Class 2.0 software patch update was promised to handle up to 24/192. Also in the works was an ASIO interface to support up to 24/192. The Invicta of course already did 24/192 over SD card, S/PDIF, AES/EBU and Toslink.